Apparatus for texturing continuous filament yarn

ABSTRACT

A method and apparatus for texturing continuous filament yarn wherein the yarn is fed at a controlled rate and under controlled tension into a confined crimping zone against a mass of crimped yarn therein causing the yarn to collapse longitudinally forming crimps which become part of such mass. Heat and pressure are applied to the yarn mass in the crimping zone to plastically deform the yarn and partially set the crimps. The crimped yarn mass is then fed at a controlled rate from the crimping zone into a setting zone. Heat and pressure are applied to the yarn mass in the setting zone to fully set the crimps. The pressure applied to the yarn mass in the setting zone is substantially only sufficient to keep the crimps closed during the final setting thereof. The crimped yarn mass is then fed from the setting zone into a cooling zone. The yarn mass is cooled in the cooling zone to a temperature below that at which the yarn undergoes any molecular structural alteration in the absence of the application of a substantial force thereto. Finally, the yarn is withdrawn at a controlled rate from the cooling zone in continuous filament form.

United States Patent Trifunovic et al.

1 1 July 15, 1975 APPARATUS FOR TEXTURING Primary ExaminerLouis K.Rimrodt CONTlNUOUS FILAMENT YARN Armr iey, Agent, or F1'rm-Schuyler.Birch, Swindler, [75] Inventors: Alexander L. Trifunovic, McKle &Beckett Wilmington, Del.; William H. Hills, Melbourne; Milton H.Bergman, [57] ABSTRACT Satellite Beach. both of Fla.; Emory p MersereauWilmington. Del. A method and apparatus for texturmg continuous filamentyarn wherein the yarn 1s fed at a controlled rate [73] Asslgnee: IndlanHead New Yorkand under controlled tension into a confined crimping 2Filed; June 1 3 zone against a mass of crimped yarn therein causing theyarn to collapse longltudinally formmg cnmps PP N03 366,164 which becomepart of such mass. Heat and pressure are applied to the yarn mass in thecrimping zone to 52 us. c1. .1 28/l.6 plsticfllly defcgrm the y nPartially Set the 511 Int. Cl. D02g 1/12 p The p ya n 18 t fed a [58]Field of Search 28/l.6, 1.7, 72.14 "Oiled rate from the ""Pf Zone e Heatand pressure are applied to the yarn mass in the 5 References Citedsetting zone to fully set the crimps. The pressure ap- UNITED STATESPATENTS plied to the yarn mass in the settlng zone substantlally onlysufficient to keep the cnmps closed during i i i the final settingthereof. The crimped yarn mass is e 1 3.046.633 7/1962 Ohashiet al 12S/16 an?" fed from i g :2 i." a cooling zone 3.096.558 7/1963 Rainardet al. 28/L6 e Yam mass C00 8 e Coo Zone 0 a 3,110,076 11/1963 Trifunvicet al. 1 1. 2811.6 Perature below that at l Y undergoes any 3 3 10/1964Eshuis v I I I l v 2 11, molecular structural alteranon 1n the absenceof the 3.353140 11/1967 Hodges et al. v i 28/116 application of asubstantial force thereto. Finally, the

3.685.109 8/1972 Torello-Viera 1 1 t v 28/].6 yarn is withdrawn at acontrolled rate from the cooling 3,707,299 l2/l972 Trifunovic v 28/l6one in continuous filament form, 3.798.7l8 3/1974 Trifunovic 28/l.6

23 Claims, Drawing Figures 196 [1 14 206 206 l I 206 4 305 a I I x 5% a22 lr by 2-10 211 s 7 4 a- \r l 252 l ii 250' 18 El J I,

/ E I Z art-1Q} 1 i .L lL 7 7 328 u ulp 4 l 52 l 6 1 L i 6 J 6 a 5 S 40I20 1 E6 9 I j I! 7o 1% Ill l m SHEET FIG.6A

APPARATUS FOR TEXTURING CONTINUOUS FILAMENT YARN BACKGROUND OF THEINVENTION 1. Field of the Invention The present invention relates tomethods and apparatus for texturing continuous filatnent yarn, and inparticular to a method and apparatus which is efficacious for crimpingcontinuous filament polyester yarn.

2. Description of the Prior Art Several methods of texturing continuousfilament polyester yarn presently are known. The methods which haveachieved the widest commercial success are those in which the yarn istextured by imparting an artificial or false twist thereto. The qualityand uniformity of the textured yarn product produced by such methodsvary widely, and production rates are limited to the texturing ofapproximately 200 yards per minute at each texturing station.

The texturing of continuous filament yarns by imparting longitudinalcrimps thereto also has been widely adopted for yarns other thanpolyester yarn, and particularly for texturing nylon yarn. However, theprior art methods of crimping continuous filament yarns and particularlyin a stuffer crimper apparatus largely have been unsuccessful forcrimping polyester yarn. This failure results primarily from thedifferent characteristics inherent in nylon and polyester yarns. In thestuffcr crimping methods presently used commercially for crimping nylonyarn, a mass of crimped yarn in the form of a crimped yarn core is fedunder pressure through a relatively long crimping tube in whichsignificant frictional forces are exerted on the core by the walls ofthe tube. Nylon yarn, due to its particular characteristics, moves at asubstantially uniform rate through the crimping tube, even whensubjected to substantial frictional forces. However, polyester yarn, dueto its different characteristics, does not move through the crimpingtube at a uniform rate but tends to move in spurts, resulting inundesirable variations in the characteristics of the crimped yarn.

SUMMARY OF THE INVENTION The method and apparatus of the presentinvention obviate the difficulties associated with use of the prior artstuffer crimper methods and apparatus for crimping polyester yarn, andmay be used advantageously for crimping other continuous filament yarns,such as nylon yarn.

Basically described, the method of the invention comprises, feedingcontinuous filament yarn at a controlled rate and under controlledtension into a confined crimping zone against a mass of crimped yarntherein causing the yarn to collapse longitudinally and fold overforming crimps which become part of the mass; applying heat and pressureto the mass in the crimping zone to plastically deform the yarn andpartially set the crimps; feeding the mass at a controlled rate from thecrimping zone to a setting zone; applying heat and pressure to the massin the setting zone to fully set the crimps, the pressure applied to themass in the setting zone being substantially only sufficient to keep thecrimps closed during the final setting thereof; feeding the mass fromthe setting zone to a cooling zone after the crimps have been fully set;cooling the mass in the cooling zone to a temperature below thetemperature at which the yarn undergoes any molecular structuralalteration in the absence of the application of a substantial forcethereto; and withdrawing the yarn at a controlled rate in continuousfilament form from the cooling zone.

Basically described, the apparatus of the invention is a stuffer crimpercomprising; a housing; a crimping chamber secured to the housing andhaving a channel extending therethrough; means for heating the chamber;a pair of opposed feed rolls rotatably mounted on the housing adjacentone end of the chamber for feeding yarn into the chamber channel; atleast one crimp control roll rotatably mounted on the housing andextending into the chamber channel, the portion of the channel betweenthe feed rolls and the crimp control roll defining a confined crimpingzone, whereby continuous filament yarn is fed into the crimping zone bythe feed rolls against a mass of crimped yarn therein in the form of acore of crimped yarn causing the yarn to collapse longitudinally andfold over forming crimps which become part of the core, the crimpcontrol roll being spaced from the feed rolls along the channel adistance no greater than the distance required for the yarn to beplastically deformed and the crimps partially set in the crimping zone,the portion of the channel between the crimp control roll and the end ofthe chamber opposite the feed rolls defining a setting zone, whereby thecore is fed into the setting zone by the crimp control roll and thecrimps are fully set therein, means for rotatably driving the pair offeed rolls at the same rotational velocity; and means for rotatablydriving the crimp control roll independently of the feed rolls, wherebythe pressure on the crimped yarn core in the crimping zone may becontrolled by regulating the relative rotational velocities of the feedrolls and the crimp control roll.

Generally, the leg length of the crimps and therefore the bulk of thecrimped yarn are controlled by regulating the pressure applied to thecrimped yarn core in the crimping zone, although other parameters, suchas heat and time of residence in the crimping zone, also affect thecharacteristics of the crimped yarn.

The pressure applied to the crimped yarn core is a function of therelative rotational velocities of the feed rolls and the crimp controlroll. Moreover, it has been found that such pressure also is a functionof the rate at which the crimped yarn core moves through the crimpingzone. Generally, as the rate at which the core moves through thecrimping zone is increased for a particular ratio of feed roll velocityto crimp control roll velocity. the pressure applied to the coredecreases and therefore the bulk of the crimped yarn also decreases.

In both the crimping and setting zones, the crimped yarn core is heatedto a temperature below the liquefaction temperature of the yarn. Thetime of residence of the core in the crimping zone is substantially lessthan the time of residence of the core in the setting and cooling zones,and in the latter two zones the frictional forces applied to the coreare minimized.

In the preferred embodiment of the apparatus of the invention, thechannel in the crimping chamber has a substantially rectangulartransverse cross-section. Desirably, the cross-sectional width of thechannel should be as small as possible, and ideally approximately equalto the diameter of the yarn. However, both structural and operationalfactors limit the minimum crosssectional width of the channel. Forexample, for wearing apparel yarn, i.e., 40-150 denier, thecrosssectional width of the channel must be at least approximately 0.10inch.

The preferred embodiment of the apparatus also includes means forfeeding yarn into the nip between the feed rolls with a traversingmotion axially of the feed rolls under controlled tension. and means forcontrolling the relative feed and withdrawal rates of yarn into and fromthe crimper.

Also, in the preferred embodiment of the apparatus, a relatively shortportion of the channel in the crimping chamber adjacent the feed rollshas a substantially elliptical transverse cross-section. This feature incombination with the traversing yarn feed to the feed rolls results inthe formation of a uniformily crimped yarn core I in the crimping zone.

The preferred embodiment of the apparatus further includes a slug whichrides freely on the top of yarn care in the cooling zone. The slug has achannel therethrough through which the yarn is withdrawn in continuousfilament form from the cooling zone. The slug also has a particularexternal configuration which facilitates withdrawal of the yarn in asubstantially slub-free condition.

With the foregoing in mind, it is an object of the present invention toprovide an improved method and apparatus for texturing continuousfilament yarn. and particularly polyester yarn.

It is a further object of the invention to provide an improved methodand apparatus for texturing continuous filament yarn by crimping suchyarn.

It is also an object of the invention to provide an improved method andapparatus for crimping continuous filament yarn which achieve a highdegree of crimp uniformity and which are operable at yarn feed speeds ofapproximately 1,000 yards per minute per crimping station.

It is an additional object of the invention to provide a method andapparatus for crimping continuous filament yarn in which high degree ofcontrol may be exercised over the bulk of the crimped yarn productproduced.

These and other objects of the invention will become apparent upon aconsideration of the detailed description of the preferred embodiment ofthe method and apparatus thereof given in connection with the followingdrawings, wherein like reference numerals identify like elementsthroughout.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of apreferred embodiment of the stuffer crimper apparatus of the invention;

FIG. 1A is a perspective view of a detail of the apparatus shown in FIG.1;

FIG. 2 is a front elevational view of the apparatus shown in FIG. I;

FIG. 3 is a longitudinal sectional view of the apparatus shown in FIG.1;

FIG. 4 is a sectional view taken on line 4-4 of FIG. 3;

FIG. 5 is a sectional view taken on line 55 of FIG.

FIG. 6 is a sectional view taken on line 6-6 of FIG.

FIG. 6A is a sectional view taken on line 6A-6A of FIG. 3;

FIG. 7. is a sectional view taken on line 77 of FIG.

FIG. 8 is a front elevational view of the crimping chamber of theapparatus shown in FIG. I;

FIG. 9 is a sectional view taken on line 9-9 of FIG.

FIG. 10 is a sectional view taken on line l0I0 of FIG. 2',

FIG. 11 is a sectional view taken on line ll --ll of FIG. 10; I 7

FIG. I2 is a layout view of the surface of the cam of the yarn feedingmeans shown in FIG. 10;

FIG. 13 is a side elevational view of a second embodiment of a yarnfeeding means which may be employed 5 in the apparatus shown in FIG. 1;

FIG. 14 is a sectional view taken on line l4l4 of FIG. 13;

FIG. 15 is a sectional view taken on line l5I5 of FIG. 1;

FIG. 16 is a sectional view taken on line l6-l6 of FIG. 15;

FIG. 17 is a perspective view of the slug employed in the apparatusshown in FIG. I; and

FIG. 18 is an enlarged sectional view of a portion of the apparatusshown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of theapparatus of the invention is a stuffer crimper designated generally byreference numeral 10. Crimper 10 includes a rear stationary housingmember I2 (FIGS. 1 and 3) which is secured to a frame 14 by bolts I6, orother suitable fasteners. A front housing member 18 is pivotallyconnected to rear housing member 12 by a shaft 20. Shaft 20 is securedto front housing member 18 by set screws 22 and is journaled forrotation in a pair of extensions 24 forming the front upper portion ofrear housing member 12.

Mounted between housing members 12 and I8 is a crimping chamber 26comprising from and rear longitudinally mated halves 28 and 30,respectively (FIGS. 3 and 9). Chamber halves 28 and 30 are made from ametallic material having relatively high heat conductivity. such as analloy of aluminum, and are secured together by a plurality of frictionfitted pins 32 and bolts 34. Assembled chamber 26 is secured to rearhousing member 12 by a plurality of bolts 35, or other suitablefasteners. Bolts 35 are inserted through openings 37 in chamber halves28 and 30 (FIG. 9) which have a slightly larger diameter than the boltsfor a purpose described hereinbelow. Chamber halves 28 and 30 definetherebetween an elongated channel 36 which extends completely throughthe chamber. A short portion of channel 36 at the lower end thereof hasa generally elliptical transverse cross-section (FIG. 6A) and theremaining portion of the channel has a substantially rectangulartransverse cross-section.

A pair of opposed feed rolls 38 and 40 are journalled in housing members18 and 12, respectively, adjacent the lower end of chamber 26 and definea nip therebetween. The lower end of the chamber defines a saddle 42which fits closely about the peripheries of the feed rolls from slightlybelow toabove the nip therebetween (FIG. 3). Saddle 42 includes a pairof arcuate surfaces 44 and 46 machined on chamber halves 28 and 30,respectively, which fit closely about thefcircumferential peripheries ofrolls 38 and 40, respectively. Also, saddle 42 includes opposed endsurfaces 48 and (FIGS. 3, 5, 6 and 8) machined on chamber halves 28 and30 which fit closely about the axial peripheries of rolls 38 and 40. Afelt pad 52 (FIG. 3) is mounted at the upper end of each of arcuatesurfaces 44 and 46 and extends outwardly from the associated surfaceinto contacting engagement with the associated rolls 38 and 40.

A pair of elongated electrical heating elements 53 and 55 (FIGS. 3, 4and 7) are inserted in the upper por- I tions of chamber halves 28 and30, respectively, and extend parallel to channel 36. Another electricalheating element 57 may be inserted in the lower portion of chamber half30 and extends transversely of channel 36.

Rolls 38 and 40 are machined as integral portions of shafts 54 and 56,respectively, (FIGS. 3 and 6). Shaft 54 is journalled in bearings 58mounted in front housing member 18, and shaft 56 is journalled inbearings 60 mounted in rear housing member 12. The outer races ofbearings 58 are accommodated in recesses 62 machined in front housingmember 18 and are locked in position therein by bearing retainers 64.Retainers 64 are secured to housing member 18 by bolts 66 (FIG. 1).Similarly, the outer races of bearings 60 are accommodated in recesses68 formed in rear housing member 12 and are locked in position thereinby bearing retainers 70. Retainers 70 are secured to housing member 12by bolts 72 (FIG. I).

A gear 74 is affixed to one end of shaft 54 and a similar gear 76 isaffixed to the same end of shaft 56. Also, a pulley 78 is affixed to theend of shaft 56 opposite gear 76. The ends of shafts 54 and 56 arethreaded and the shafts are axially locked in position with respect tobearings 58 and 60 by nuts 80 and spacers 81 (FIG. 6).

A pair of opposed crimp control rolls 82 and 84 also are journalled inhousing members 18 and I2, respectively, about axes parallel to the axesof feed rolls 38 and 40. In the preferred embodiment of the apparatus ofthe invention, the crimp control rolls have textured surfaces formed bygear-like teeth and are machined as integral portions of shafts 86 and88, respectively, (FIGS. 3 and 7). Rolls 82 and 84 are accommodatedwithin arcuate openings machined in chamber halves 28 and 30,respectively, with the peripheries of the rolls being spaced apartwithin channel 36, as shown by reference numeral 90. Shaft 86 isjournalled in bushings 92 which are accommodated in recesses 94 machinedin front housing member 18. Bushings 92 are locked in position byretainers 96 which are secured to housing member 18 by bolts 98 (FIG.1). Similarly, shaft 88 is journalled in bushings 100 which areaccommodated in recess 102 machined in rear housing member 12. Bushings100 are locked in position by retainers 104 which are secured to housingmember 12 by suitable bolts (not shown).

A gear 106 (FIG. 7) is affixed to one end of shaft 86 and a similar gear108 is affixed to the same end of the shaft 88. Also, a pulley 114 isaffixed to the same end of shaft 88 as gear 108, outwardly of the gear.Shafts 86 and 88 are axially locked in position with respect to bushings92 and 100 by spring clips and clamps 112.

When front housing member 18 is pivoted rearwardly about the axis ofshaft 20 to the position shown in solid lines in FIG. 1, gear 74 mesheswith gear 76 and gear 106 meashes with gear 108. Also, thecircumferential periphery of feed roll 38 contacts the circumferentialperiphery of feed roll 40 forming a nip therebetween. The teeth of gears74, 76,106 and 108 are elongated sufficiently to insure that the gearswill mesh properly when the feed rolls are in contact with each other.

Crimper 10 also includes means for urging front housing member 18rearward toward rear housing member 12. Such means include a split frame118 which is affixed to front housing member 18 by bolts 120, or othersuitable fasteners. Frame 118 extends downwardly and inwardly from thelower end of housing member 18 (FIGS. 1 and 2), and a handle 122 isremovably connected to the lower end thereof.

A flexible cable 124 extends through the back of handle 122 and isslidably connected thereto by a disc I26 affixed to the end of the cable(FIG. 1A). Cable 124 passes around a pulley 128, and a weight is affixedto the other end thereof. Pulley 128 is mounted on a shaft 132 which isjournalled in a pair of arms 134 affixed to frame 14.

Aftixed to the lower end of frame 118 are a pair of horizontally alignedpins 136 which are adapted to register with and engage a pair ofopenings 138 in the back of handle 122. As will be apparent, when pins136 are engaged with openings 138, weight 130, via cable 124, urgesframe 118 and front housing member 18 rearwardly toward rear housingmember 12, thus insuring that the circumferential periphery of feed roll38 contacts the circumferential periphery of feed roll 40.

When it is desired to pivot front housing member 18 away from rearhousing member 12, as shown in phantom lines in FIG. I, handle 122 ispulled outwardly so that pins 136 disengage openings 138, thus releasingframe 118. For convenience, a pair of pins 140 similar to pins 136 areaffixed to frame 14 and are adapted to register with and engage openings138 to hold handle 122 against the frame in the position shown inphantom lines in FIG. 1 when housing member 18 is pivoted away fromhousing member 12.

Crimper 10 further includes means mounted below feed rolls 38 and 40 forfeeding yarn to the nip between the feed rolls. The yarn feeding meansincludes a split cam 142 (FIG. 10 and 11). Cam 142 comprises a pair ofaxially opposed, cylindrical yarn guiding members 144 and 146 which areaffixed, respectively, to a pair of circular flanges 148 and 150.Flanges 148 and 150 are mounted on a shaft 152 having an enlargedcylindrical central portion 154. Flanges 148 and 150 accommodate theends of enlarged shaft portion 154, and are connected together by aplurality of circumferentially spaced rods 156. The ends of rods 156 arethreaded and receive nuts 158 thereon which lock flanges 148 and 150onto shaft 152. Guiding members 144 and 146 define a helical slot 160(FIG. 12) therebetween through which yarn is fed to feed rolls 38 and 40as described hereinbelow.

Shaft 152 is journalled about an axis parallel to the axes of feed rolls38 and 40 in bushings 162 which are accommodated in a pair of arms 164affixed to frame 14. Bushings 162 are locked in position by retainers166 which are secured to arms 164 by bolts 168 (FIGS. 1 and 10). Alsomounted on shaft 152 and interposed between flange 150 and the adjacentbushing 162 is a 5 pulley- 170.

A pair of pulleys 172 and 174 (FIG. 1) are mounted on a shaft 176 whichis journalled about an axis parallel to the axes of feed rolls 38 and 40in bushings 178.

Bushings 178 are accommodated in a pair of arms 180 affixed to frame 14,and are locked in position by retainers 182 which are secured to arms180 by bolts 184.

A belt 186 is trained about pulleys 78, 170 and 172 so that feed rolls38 and 40 are driven in synchronism with cam 142. A belt 188 is trainedabout pulley 174 and a pulley (not shown) connected to an appropriatedriving means (not shown), such as an electric motor, for driving feedrolls 38 and 40 and cam 142.

A belt 190 is trained about pulley 114 and a pulley 192 affixed to theoutput shaft of a transmission 194. An electric motor (not shown) isdrivingly connected to transmission 194 for rotating crimp control rolls82 and 84.

Appropriate openings are formed in frame 14 to permit the passage ofcable 124, and belts 186 and 190 therethrough.

Crimper 10 further includes a cooling tower 196 (FIGS. 1, 2, l and 16)affixed to the upper end of crimping chamber 26. Tower 196 comprises apair of longitudinally mated halves 198 and 200 which define a channel202 therebetween. Channel 202 is vertically aligned with channel 36 inchamber 26. Members 198 and 200 are connected together at the lower endsthereof and to right-angle flanges 206 by bolts 204. Flanges 206 aresecured to the upper end of chamber 26 by bolts 208. A longitudinallyextending transverse opening 210 is formed in the side of each ofmembers 198 and 200 to permit a coolant, such as compressed air, to becirculated into and through tower 196.

A slug 212 rides freely in the upper end of channel 202 on the top of acore of crimped yarn therein. The formation of the core and the movementthereof through crimper are described hereinbelow. Slug 212 (FIG. 17)has an upper parallelepiped shaped portion 214 and a lower generallypyramidal shaped portion 216. Lower portion 216 includes a pair ofleg-like members 218 and 220 which extend downwardly and outwardly atopposite sides thereof. Members 218 and 220 extend downwardly slightlybelow the central section of the lower end of lower portion 216. Achannel 222 having an elliptically shaped transverse crosssectionextends longitudinally through slug 212. Also, a small permanent magnet224 is attached to one side of upper portion 214 for a purpose describedhereinbelow.

A case 226 is mounted on the side of member 198 adjacent the upper endthereof. A plurality of bolts 228 extend through case 226 and member 198and are threadably received by member 200, and thereby secure the caseto member 198 and connect members 198 and 200 together at the upper endsthereof. Mounted within case 226 are four vertically spaced,magnetically sensitive reed switches 230, 232, 234 and 236.

Member 198 has a longitudinally extending transverse opening 238 thereinadjacent switches 230, 232, 234 and 236. As slug 212 moves verticallyupwardly and downwardly with the upper end of the core of crimped yarn,magnet 224 moves into and out of proximity with switches 230, 232, 234and 236, and selectively closes and opens the switches. Electrical leads240. 242, 244 and 246 connect switches 230, 232, 234 and 236,respectively, to various electrical circuits to control the operation ofcrimper 10 as described hereinbelow.

Crimper 10 is constructed in such a manner as to facilitate the properalignment of feed rolls 38 and 40 with each other and with saddle 42.During the manufacture of the crimper, channel 36 is machined in chamberhalf 28 (FIG. 4), and chamber halves 28 and 30 are then connectedtogether by pins 32 and bolts 34. Saddle 42 is then machined at thelower end of assembled chamber 26. A plurality of members, such as studs248, are inserted in the rear side of chamber 26 and project outwardlytherefrom. At least two of studs 248 on the left side of the chamber asseen in FIG. 5, define a line parallel to channel 36. The diameter ofthe studs is accurately controlled and the ends thereof are machined sothat the distance between such ends and the rear wall of channel 36 isconstant.

The inner surfaces of rear housing member 12 include vertical machinedsurfaces 250 and 252. Surfaces 250 and 252 are perpendicular to eachother and define a pair of reference planes which contact studs 248 toproperly position chamber 26 transversely (side-toside) and laterally(front-to-rear) with respect to rear housing member 12. As shown inFIGS. 4 and 5 this result is achieved by placing the two studs 248 onthe left side of chamber 26 as seen in FIG. 5 against surface 250 andthe ends of the studs against surface 252.

The distance between surface 252 and the journals for shaft 20 inextensions 24 of rear housing member 12 also is carefully determined sothat shaft 20 is accurately positioned with respect to reference surface252. In this manner, front housing member 18 is accurately positionedwith respect to rear housing member 12.

Also, bearing recesses 62 and 68 and bushing recesses 94 and 102 areaccurately machined with respect to the position of shaft 20. In thismanner, feed rolls 38 and 40 and crimp control rolls 82 and 84 areaccurately positioned with respect to each other.

During assembly of crimper 10, chamber 26 is first connected to rearhousing member 12 by bolts 35 which initially are not securelytightened. Front housing member 18 is then connected to rear housingmember 12 by shaft 20. Bearings 58 and and bushings 92 and are thenmounted in recesses 62, 68, 94 and 102, respectively. Feed rolls 38 and40 and crimp control rolls 82 and 84 are then adjusted axially withrespect to saddle 42, and retainers 64 and 70, and 96 and 104 aresecured to the respective housing members to lock the feed rolls andcrimp control rolls in position. Finally, chamber 26 is adjustedlongitudinally (vertically) with respect to feed rolls 38 and 40 toprovide the proper clearance between the feed rolls and saddle 42, andbolts 35 are tightened to secure chamber 26 to rear housing member 12.

A second embodiment of a yarn feeding meanns which may be employed withcrimper 10 is shown in FIGS. 13 and 14 and comprises a split cam 300.Cam 300 includes a pair of axially and circumferentially opposed,generally semi-circular guiding members 302 and 304. Member 302 definesa helical yarn guiding surface 306, and member 304 defines a similarguiding surface 308 which is axially and circumferentially opposed tosurface 306. Members 302 and 304 are affixed to shaft 152 by a pluralityof threaded rods 310 and nuts 312. Axially interposed between members302 and 304 is a generally elliptically shaped cam 314 which is securedabout enlarged shaft portion 154 by rods 310.

As shown in FIG. 13, guiding members 302 and 304 overlap slightlycircumferentially, with member 302 having a trailing edge finger 316 andmember 304 having a trailing edge finger 318. The function of surfaces306 and 308 and cam 314 is described hereinbelow.

The method of the invention will now be described in detail withreference to crimper 10. Continuous filarnent yarn 320 is fed from aspool of such yarn or other source of yarn supply through a conventionaltension control mechanism 322 (FIG. 1) upwardly into slot 160 of cam142. Slot 160 guides the yarn into the nip between feed rolls 38 and 40with a traversing movement back and forth axially of the feed rolls.

In order to obtain uniform feeding of the yarn into the nip, both withrespect to yarn quantity and orientation, it is necessary that tensionof a controlled magnitude be applied to the yarn between mechanism 322and feed rolls 38 and 40.

Also, a conventional prehcater 325 may be interposed between mechanism322 and cam 142 to preheat yarn 320 prior to the crimping thereof.Generally, it has been found desirable to preheat yarn which is heavierthan two denier per filament. Preheating softens the yarn andfacilitates the crimping thereof.

As the yarn passes through cam 142, it contacts rods 156 as shown inFIG. 11. Rods 156 are polished so that friction between the rods and theyarn is minimized. Should the yarn break within cam 142 and becomewrapped around rods 156, it is much simpler to untangle the yarn fromsuch rods than it is from around a continuous groove or shaft. In orderto permit easy access to the interior of cam 142, flanges I48 and 150have openings 324 and 326 therein, respectively.

As shown most clearly in FIG. 2, as slot 160 traverses yarn 320 back andforth axially of the feed rolls, the yarn is fed by the feed rolls intochannel 36 in a substantially uniform manner back and forth across thecross-sectional dimension of the channel parallel to the axes of thefeed rolls, i.e. the cross sectional length of the channel.

If desired, the yarn feeding means comprising split cam 300 may besubstituted for the feeding means comprising cam 142. As the yarn is fedthrough cam 300, it rides on elliptical cam 314 and is traversed backand forth axially of the feed rolls by guiding surfaces 306 and 308 inthe same manner as it is traversed by slot 160 of cam 142. Ellipticalcam 314 is designed such that the length of yarn between such cam andthe nip between feed rolls 38 and 40 remains substantially constant. Theportions of cam 314 along the long axis thereof engage the yarn as it isfed through the midportion of the feed rolls, and the portions of thecam along the short axis thereof engage the yarn as it is fed throughthe end portions of the feed rolls. This arrangement insures that theyarn will not become slack at any point as it is traversed axially ofthe feed rolls. Also, since guiding members 302 and 304 encompass onlyslightly greater than one half of the circumference of cam 300, accessto the yarn in the feeding means is greatly facilitated.

Immediately after passage between the feed rolls, the yarn is fedagainst a mass of crimped yarn in the form ofa core of crimped yarn 328(FIG. 3) in the lower end of channel 36, causing the yarn to collapselongitudinally and fold over forming crimps which become part of thecore. The generally elliptical transverse crosssectional configurationof the lower portion of channel 36 minimizes voids in the channel in thezone immediately above the feed rolls so that a substantially uniformcrimping pressure will be applied to the yarn after it passes betweenthe feed rolls. The portion of channel 36 between feed rolls 38 and 40and crimp control rolls 82 and 84 comprises a crimping zone in which theyarn initially is set. The crimp control rolls effectively isolate thecrimping zone from the portion of channel 36 thereabove. By controllingthe relative rotational velocities of the feed rolls and the crimpcontrol rolls, the back pressure or crimping force exerted on the yarnmay be accurately controlled. Generally, for a yarn of a particulardenier, an increase in the crimping force results in a decrease in theleg length of the crimps and an increase in the bulk of the crimpedyarn. The crimping force may be increased by decreasing the rotationalvelocity of crimp control rolls 82 and 84 with respect to the rotationalvelocity of feed rolls 38 and 40. The yarn is crimped and plasticallydeformed in the crimping zone. However, the heat and pressure applied tocore 328 and the time of residence of the core in the crimping zone isinsufficient to cause the yarn to be set permanently, and in the absenceof pressure on the core the crimps will open freely after passagethrough the crimping zone. Moreover, for polyester yarn, it is desirablethat the residence time of the yarn in the crimping zone be relativelyshort to minimize the effects of friction on the formation of thecrimps, and therefore, the distance between feed rolls 38 and 40 andcrimp control rolls 82 and 84 along channel 36 is relatively short. Thisarrangement facilitates accurate control of the conditions within thecrimping zone, with the frictional forces exerted on the yarn by thewalls of channel 36 in the crimping zone having little or no effect onsuch conditions.

Also, desirably the cross-sectional dimension of channel 36 in thedirection perpendicular to the axes of feed rolls 38 and 40, i.e., thecross-sectional width of the channel, should be as small as possible topromote uniform heat transfer from chamber 26 to and through core 328.Ideally, the cross-sectional width of channel 36 should be approximatelyequal to the diameter of yarn 320. However, at least two factors limitthe minimum cross-sectional width of the channel. First. as thecross-sectional width of the channel is decreased, the angle definedbetween each of the side walls of the channel which extend in thedirection parallel to the feed roll axes and respective arcuate surfaces44 and 46 also is decreased (FIG. 18). If such angle is made too small,the adjacent portion of saddle 42 does not possess sufficient strengthto withstand the pressure exerted thereagainst by core 328 withoutdeforming or fracturing. Second, as such angle is decreased, the apexthereof necessarily is moved downwardly closer to the nip between feedrolls 38 and 40. If the apex of the angle is moved too close to the nipbetween the feed rolls. as yarn 320 is fed through the nip, the yarnwill tend to move under surfaces 44 and 46 between such surfaces andfeed rolls 38 and 40 rather than into channel 36. Due to these factors,it has been found that an angle a which is defined between the verticalprojection of each of the side walls of the channel which extend in thedirection parallel to the feed roll axes and a plane tangent to theadjacent feed roll must be at least approximately 23, as shown inphantom lines in FIG. 18 and identified as angle am (minimum 0:). Anglea is substantially identical to the angle defined by such walls andsurfaces 44 and 46. In the preferred embodiment of crimper l0, angle ais approximately 29, as

shown in solid lines in FIG. 18 and identified as angle ozp (preferredFurther, it has been found that the cross-sectional width of channel 36in relation to the cross-sectional area of yarn 320 has an importanteffect on the operation of the crimper. For example, for wearing apparelyarn, i.e., 40-150 denier, the ratio of the crosssectional width of thechannel in inches to the yarn denier should be in the range of fromabout 0.000667 to about 0.00425; the cross-sectional area of the yarnbeing proportional to the denier thereof. Preferably, such ratio is inthe range of from about 0.001 to about 0.004. If the cross-sectionalwidth of channel 36 is reduced below an amount required to satisfy theabovementioned range of values for such ratio, the yarn will tend tomove under surfaces 44 and 46 between such surfaces and feed rolls 38and 40. For yarn having a denier in the range of 40-150, thecross-sectional width of the channel should be in the range of fromabout 0.l0 inch to about 0.17 inch, and preferably is about 0.16 inch.

Felt pads 52 prevent yarn 320 from moving out of the crimper betweenfeed rolls 38 and 40 and arcuate surfaces 44 and 46, respectively, andparticularly during start-up of the crimper before core 328 fills thecrimping zone.

Crimp control rolls 82 and 84 feed core 328 upwardly out of the crimpingzone and past such rolls into the portion of channel 36 above the crimpcontrol rolls. The portion of channel 36 which extends between crimpcontrol rolls 82 and 84 and the upper end of chamber 26 comprises asetting zone in which the core is subjected to heating and pressure onlysufficient to keep the crimps formed in the crimping zone closed. Theonly pressure exerted on the core in the setting zone is the weight ofthe core itself and the relatively light weight of slug 212 which rideson the upper end thereof. In the setting zone, the yarn is fully set.Due to the relatively small amount of pressure exerted on the core inthe setting zone, the frictional forces applied thereto in such zone areminimized. This is particularly important in the crimping of polyesteryarn due to the undesirable effects which relatively large frictionalforces have on the crimping of such yarn.

After passage through the setting zone, core 328 is fed into channel 202of cooling tower 196 in which the yarn is cooled below the temperatureat which it undergoes any molecular structural alteration in the absenceof the application of a substantial force thereto. If desired, anddepending upon the necessity therefore, a coolant, such as compressedair, may be introduced into and circulated through the core throughopenings 210.

The crimped yarn is withdrawn from channel 202 through channel 222 inslug 212 in continuous filament form by a conventional winder 330 onwhich it is wound into cones for further processing, as desired.

The external configuration and dimensions of slug 212 are important tosmooth, substantially slub-free withdrawal of the yarn from coolingtower 196. The only portions of the slug which contact the upper end ofcore 328 are leg-like members 218 and 220 (FIG. The portions of the corecontacted by members 218 and 220 are positioned adjacent the shortcrosssectional transverse dimension of channel 202 and are the portionsin which the yarn feed direction, axially of the feed rolls, is reversedby cam 142 or split cam 300.

Members 218 and 220 apply a slight pressure, namely the weight of slug212, on such portions and thereby require that a relatively smallincrease in tension be applied to the yarn to pull it out from under themembers. The application of this increased tension pulls substantiallyall of the tangles out of the yarn and thereby minimizes the occurrenceof slubs. The central section of lower portion 216 does not contact core328 so that there is no impedance to the withdrawal of yarn from thecentral portion of the core. Also the long external, transversecross-sectional dimension of both upper portions 214 and lower portion216 is less than the long transverse cross-sectional dimension ofchannel 202 so that slug 212 can rock back and forth slightly on members218 and 220 to accommodate slight differences in the height of the endportions of the core.

As the yarn is withdrawn from tower 196, the upper end of core 328, andtherefore slug 212, move vertically upwardly and downwardly asdetermined by the rate at which the yarn is withdrawn in relationship tothe rate of upward movement of the core. Magnet 224 and reed switches230, 232, 234 and 236 cooperate to control the height of the core.

Upper switch 230 and lower switch 236 are safety limit switches. Whenmagnet 224 moves into proximity with upper switch 230 closing suchswitch, the driving means for crimper l0 (cam 142, feed rolls 38 and 40and crimp control rolls 82 and 84) are deactivated. When the magnetmoves into proximity with lower switch 236 closing such switch, thedriving means for both crimper l0 and winder 330 are deactivated. Theseare both abnormal conditions and occur only under other than normaloperating conditions, such as when the yarn breaks either between thecrimper and winder or between the source of yarn supply and feed rolls38 and 40.

During normal operating conditions, magnet 224 moves vertically upwardlyand downwardly between switches 232 and 234', both of which are operablyconnected to the winder driving means. When magnet 224 moves intoproximity with switch 232 closing such switch, winder 330 is driven at100% of a predetermined speed. Such predetermined speed is slightlygreater than the speed required to withdraw the yarn from tower 196 atthe same rate at which it is fed into the tower. Therefore, the upperend of core 328 and slug 212 gradually move downwardly until magnet 224moves into proximity with switch 234 closing such switch and permittingswitch 232 to open. When switch 234 is closed, the winder is driven at aspeed less than the aforementioned predetermined speed, for example, atpercent of the predetermined speed. At such lower speed the winderwithdraws yarn at a rate slightly less than that at which it is fed intotower 196. Thus, the upper end of the core and slug 212 move upwardlyuntil magnet 224 again moves into proximity with switch 232 closing suchswitch and permitting switch 234 to open, again causing the winder tooperate at percent of the predetermined speed. In this manner, the upperend of the core and the slug move upwardly and downwardly continuously adistance approximately equal to the distance between switches 232 and234, thus maintaining the upper end of the core within a predeterminedrange.

The foregoing method is particularly efficacious for crimping polyesteryarn due to the substantial elimina tion of the effect of frictionalforces on the core of crimped yarn as such core moves through crimper10, and is advantageous for crimping other continuous filament yarns,such as nylon yarn.

While the foregoing constitutes a detailed description of a preferredembodiment of the method and apparatus of the invention, it isrecognized that modifications thereof will occur to those skilled in theart. Accordingly, the scope of the invention is to be limited solely bythe scope of the appended claims.

We claim:

1. A stuffer crimper for crimping continuous filament yarn having adenier in the range of approximately 40-150, said crimper comprising:

a housing;

a crimping chamber secured to said housing and having a channelextending therethrough, said channel having a generally rectangulartransverse crosssection;

means for heating said chamber;

a pair of opposed feed rolls rotatably mounted on said housing adjacentone end of said chamber for feeding yarn into said chamber channel, thelong cross-sectional dimension of said channel extending parallel to therotational axes of said feed rolls and the short cross-sectionaldimension of said channel extending perpendicular to said axes, theratio of said short cross-sectional dimension in inches to the denier ofsaid yarn having a minimum value of about 0.000667;

at least one crimp control roll rotatably mounted on said housing andextending into said chamber channel, the portion of said channel betweenthe feed rolls and the crimp control roll defining a confined crimpingzone, whereby continuous filament yarn is fed into said crimping zone bythe feed rolls against a core of crimped yarn therein causing the yarnto collapse longitudinally and fold over forming crimps which becomepart of said core, the crimp control roll being spaced from the feedrolls along said channel a distance no greater than the distancerequired for the yarn to be plastically deformed and partially set insaid crimping zone, the portion of said channel between the crimpcontrol roll and the end of the chamber opposite the feed rolls defininga setting zone, whereby said core is fed into the setting zone by thecrimp control roll and the yarn is fully set therein;

means for rotatably driving said pair of feed rolls at the samerotational velocity; and

means for rotatably driving said crimp control roll independently ofsaid feed rolls, whereby the pressure on the crimped yarn core in saidcrimping zone may be controlled by regulating the relative rotationalvelocities of the feed rolls and the crimp control roll.

2. A stuffer crimper as recited in claim 1, wherein said chamber is madefrom a metallic material having relatively high heat conductivity.

3. A stuffer crimper as recited in claim 1; comprising a pair of opposedcrimp control rolls, the peripheries of said crimp control rolls beingspaced apart within said chamber channel; and wherein said crimp controlroll driving means drives said pair of crimp control rolls at the samerotational velocity.

4. A stuffer crimper as recited in claim 1, wherein a portion of saidchamber channel adjacent said feed rolls has a generally ellipticaltransverse cross-section.

5. A stuffer crimper as recited in claim 1, wherein said crimp controlroll is mounted for rotation about an axis parallel to the axes of saidfeed rolls.

6. A stuffer crimper as recited in claim 1, further comprising means forpre-heating the yarn before the yarn is fed into said chamber channel.

7. A stuffer crimper as recited in claim 1, further comprising means forapplying controlled tension to the yarn before the yarn is fed into saidchamber channel.

8. A stuffer crimper as recited in claim 1, further comprising a pair offelt pads, said pads being interposed between said respective feed rollsand said chamber.

9. A stuffer crimper as recited in claim 1, further comprising means forfeeding yarn to said feed rolls and traversing the yarn axially thereof.

10. A stuffer crimper as recited in claim 9, wherein said feeding meanscomprises a rotatably mounted cam having a helical slot therein, saidcam being mounted for rotation about an axis parallel to the axes ofsaid feed rolls.

1]. A stuffer crimper as recited in claim 10, wherein said cam comprisesa pair of axially opposed guiding members each defining one side of saidslot.

12. A stuffer crimper as recited in claim 11, wherein said guidingmembers are connected together by a plurality of rods, whereby the yarnrides on said rods as the yarn is fed between the guiding members.

l3. A stuffer crimper as recited in claim 9, wherein said feeding meanscomprises a pair of circumferentially and axially opposed guidingmembers each defining a yarn guiding surface. said members beingconnected together and mounted for rotation about an axis parallel tothe axes of said feed rolls.

14. A stuffer crimper as recited in claim 13, wherein a generallyelliptically shaped cam is axially interposed between said guidingmembers, whereby the yarn rides on said cam as the yarn is fed betweenthe guiding members; and wherein the portions of said cam along the longaxis thereof engage the yarn as the yarn is fed through the midportionof the feed rolls and the portions of said cam along the short axisthereof engage the yarn as the yarn is fed through the end portions ofthe feed rolls, whereby the length of yarn between the feeding means andthe feed rolls is maintained substantially constant.

15. A stuffer crimper for crimping continuous filament yarn comprising:

a housing having at least two perpendicularly oriented referencesurfaces thereon;

a crimping chamber having a channel extending therethrough and at leasttwo members projecting therefrom, said members defining a line parallelto said channel and the outer ends thereof being the same distance froma wall of said channel, said members contacting said housing referencesurfaces for accurately positioning said chamber with respect to saidhousing along two perpendicular axes;

means for securing said chamber to said housing for adjustment along anaxis perpendicular to said two axes;

means for heating said chamber,

a pair of opposed feed rolls rotatably mounted on said housing adjacentone end of said chamber for feeding yarn into said chamber channel;

at least one crimp control roll rotatably mounted on said housing andextending into said chamber channel, said crimp control roll beingspaced from said feed rolls along said channel, the portion of saidchannel between the feed rolls and the crimp control roll defining aconfined crimping zone, whereby continuous filament yarn is fed intosaid crimping zone by the feed rolls against a core of crimped yarntherein causing the yarn to collapse longitudinally and fold overforming crimps which become part of said core and the crimps arepartially set in the crimping zone, the portion of said channel betweenthe crimp control roll and the end of the chamber opposite the feedrolls defining a setting zone, whereby said core is fed into saidsetting zone by the crimp control roll and crimps are fully set therein;

means for rotatably driving said pair of feed rolls at the samerotational velocity; and

means for rotatably driving said crimp control roll independently ofsaid feed rolls, whereby the pressure on the crimped yarn core in saidcrimping zone may be controlled by regulating the relative rotationalvelocities of the feed rolls and the crimp control roll.

16. A stuffcr crimper as recited in claim 15; wherein lid housingcomprises a front housing member and a :ar housing member, said frommember being movoly connected to said rear member; and wherein saidousing reference surfaces are on said rear housing iember.

17. A stuffer crimper for crimping continuous filaient yarn having adenier in the range of approxiiately 40-150, said crimper comprising:

a housing;

a crimping chamber secured to said housing and having a channelextending therethrough, said channel having a generally rectangulartransverse crosssection;

means for heating said chamber;

a pair of opposed feed rolls rotatably mounted on said housing adjacentone end of said chamber for feeding yarn into said chamber channel, thelong cross-sectional dimension of said channel extending parallel to therotational axes of said feed rolls and the short cross-sectionaldimension of said channel extending perpendicular to said axes, theratio of said short cross-sectional dimension in inches to the denier ofsaid yarn being in the range of from about 0.000667 to about 0.00425;

at least one crimp control roll rotatably mounted on said housing andextending into said chamber channel, said crimp control roll beingspaced from said feed rolls along said channel, the portion of saidchannel between the feed rolls and the crimp control roll defining aconfined crimping zone, whereby continuous filament yarn is fed intosaid crimping zone by the feed rolls against a core of crimped yarntherein causing the yarn to collapse longitudinally and fold overforming crimps which become part of said core and the crimps arepartially set in the crimping zone, the portion of said channel betweenthe crimp control roll and the end of the chamber opposite the feedrolls defining a setting zone, whereby said core is fed into saidsetting zone by the crimp control roll and the crimps are fully settherein;

means for rotatably driving said pair of feed rolls at the samerotational velocity; and

means for rotatably driving said crimp control roll independently ofsaid feed rolls, whereby the pressure on the crimped yarn core in saidcrimping zone may be controlled by regulating the relative rotationalvelocities of the feed rolls and the crimp control roll.

18. A stuffer crimper as recited in claim 17, wherein said shortcross-sectional dimension is in the range of from about 0.100 inch toabout 0.170 inch.

19. A stuffer crimper as recited in claim 17, wherein said ratio is inthe range of from about 0.001 to about 0.004.

20. A stuffer crimper as recited in claim 19, wherein said shortcross-sectional dimension is about 0.160 inch.

21. A stuffer crimper as recited in claim I, further comprising acooling tower affixed at one end thereof to said chamber at the end ofthe chamber opposite said feed rolls and having a channel extendingtherethrough aligned with said chamber channel, said tower channeldefining a cooling zone, whereby the crimped yarn core is fed into saidcooling Zone after passage through said setting zone and the yarn iscooled therein.

22. A stuffer crimper as recited in claim 21, further comprising meansfor withdrawing yarn from said tower channel.

23. A stuffer crimper as recited in claim 22, wherein said withdrawingmeans comprises a winder.

1. A stuffer crimper for crimping continuous filament yarn having adenier in the range of approximately 40-150, said crimper comprising: ahousing; a crimping chamber secured to said housing and having a channelextending therethrough, said channel having a generally rectangulartransverse cross-section; means for heating said chamber; a pair ofopposed feed rolls rotatably mounted on said housing adjacent one end ofsaid chamber for feeding yarn into said chamber channel, the longcross-sectional dimension of said channel extending parallel to therotational axes of said feed rolls and the short cross-sectionaldimension of said channel extending perpendicular to said axes, theratio of said short cross-sectional dimension in inches to the denier ofsaid yarn having a Minimum value of about 0.000667; at least one crimpcontrol roll rotatably mounted on said housing and extending into saidchamber channel, the portion of said channel between the feed rolls andthe crimp control roll defining a confined crimping zone, wherebycontinuous filament yarn is fed into said crimping zone by the feedrolls against a core of crimped yarn therein causing the yarn tocollapse longitudinally and fold over forming crimps which become partof said core, the crimp control roll being spaced from the feed rollsalong said channel a distance no greater than the distance required forthe yarn to be plastically deformed and partially set in said crimpingzone, the portion of said channel between the crimp control roll and theend of the chamber opposite the feed rolls defining a setting zone,whereby said core is fed into the setting zone by the crimp control rolland the yarn is fully set therein; means for rotatably driving said pairof feed rolls at the same rotational velocity; and means for rotatablydriving said crimp control roll independently of said feed rolls,whereby the pressure on the crimped yarn core in said crimping zone maybe controlled by regulating the relative rotational velocities of thefeed rolls and the crimp control roll.
 2. A stuffer crimper as recitedin claim 1, wherein said chamber is made from a metallic material havingrelatively high heat conductivity.
 3. A stuffer crimper as recited inclaim 1; comprising a pair of opposed crimp control rolls, theperipheries of said crimp control rolls being spaced apart within saidchamber channel; and wherein said crimp control roll driving meansdrives said pair of crimp control rolls at the same rotational velocity.4. A stuffer crimper as recited in claim 1, wherein a portion of saidchamber channel adjacent said feed rolls has a generally ellipticaltransverse cross-section.
 5. A stuffer crimper as recited in claim 1,wherein said crimp control roll is mounted for rotation about an axisparallel to the axes of said feed rolls.
 6. A stuffer crimper as recitedin claim 1, further comprising means for pre-heating the yarn before theyarn is fed into said chamber channel.
 7. A stuffer crimper as recitedin claim 1, further comprising means for applying controlled tension tothe yarn before the yarn is fed into said chamber channel.
 8. A stuffercrimper as recited in claim 1, further comprising a pair of felt pads,said pads being interposed between said respective feed rolls and saidchamber.
 9. A stuffer crimper as recited in claim 1, further comprisingmeans for feeding yarn to said feed rolls and traversing the yarnaxially thereof.
 10. A stuffer crimper as recited in claim 9, whereinsaid feeding means comprises a rotatably mounted cam having a helicalslot therein, said cam being mounted for rotation about an axis parallelto the axes of said feed rolls.
 11. A stuffer crimper as recited inclaim 10, wherein said cam comprises a pair of axially opposed guidingmembers each defining one side of said slot.
 12. A stuffer crimper asrecited in claim 11, wherein said guiding members are connected togetherby a plurality of rods, whereby the yarn rides on said rods as the yarnis fed between the guiding members.
 13. A stuffer crimper as recited inclaim 9, wherein said feeding means comprises a pair ofcircumferentially and axially opposed guiding members each defining ayarn guiding surface, said members being connected together and mountedfor rotation about an axis parallel to the axes of said feed rolls. 14.A stuffer crimper as recited in claim 13, wherein a generallyelliptically shaped cam is axially interposed between said guidingmembers, whereby the yarn rides on said cam as the yarn is fed betweenthe guiding members; and wherein the portions of said cam along the longaxis thereof engage the yarn as the yarn is fed through the midportionof the feed rolls and the portions of said cam along the short axisthereof engage the yArn as the yarn is fed through the end portions ofthe feed rolls, whereby the length of yarn between the feeding means andthe feed rolls is maintained substantially constant.
 15. A stuffercrimper for crimping continuous filament yarn comprising: a housinghaving at least two perpendicularly oriented reference surfaces thereon;a crimping chamber having a channel extending therethrough and at leasttwo members projecting therefrom, said members defining a line parallelto said channel and the outer ends thereof being the same distance froma wall of said channel, said members contacting said housing referencesurfaces for accurately positioning said chamber with respect to saidhousing along two perpendicular axes; means for securing said chamber tosaid housing for adjustment along an axis perpendicular to said twoaxes; means for heating said chamber; a pair of opposed feed rollsrotatably mounted on said housing adjacent one end of said chamber forfeeding yarn into said chamber channel; at least one crimp control rollrotatably mounted on said housing and extending into said chamberchannel, said crimp control roll being spaced from said feed rolls alongsaid channel, the portion of said channel between the feed rolls and thecrimp control roll defining a confined crimping zone, whereby continuousfilament yarn is fed into said crimping zone by the feed rolls against acore of crimped yarn therein causing the yarn to collapse longitudinallyand fold over forming crimps which become part of said core and thecrimps are partially set in the crimping zone, the portion of saidchannel between the crimp control roll and the end of the chamberopposite the feed rolls defining a setting zone, whereby said core isfed into said setting zone by the crimp control roll and crimps arefully set therein; means for rotatably driving said pair of feed rollsat the same rotational velocity; and means for rotatably driving saidcrimp control roll independently of said feed rolls, whereby thepressure on the crimped yarn core in said crimping zone may becontrolled by regulating the relative rotational velocities of the feedrolls and the crimp control roll.
 16. A stuffer crimper as recited inclaim 15; wherein said housing comprises a front housing member and arear housing member, said front member being movably connected to saidrear member; and wherein said housing reference surfaces are on saidrear housing member.
 17. A stuffer crimper for crimping continuousfilament yarn having a denier in the range of approximately 40-150, saidcrimper comprising: a housing; a crimping chamber secured to saidhousing and having a channel extending therethrough, said channel havinga generally rectangular transverse cross-section; means for heating saidchamber; a pair of opposed feed rolls rotatably mounted on said housingadjacent one end of said chamber for feeding yarn into said chamberchannel, the long cross-sectional dimension of said channel extendingparallel to the rotational axes of said feed rolls and the shortcross-sectional dimension of said channel extending perpendicular tosaid axes, the ratio of said short cross-sectional dimension in inchesto the denier of said yarn being in the range of from about 0.000667 toabout 0.00425; at least one crimp control roll rotatably mounted on saidhousing and extending into said chamber channel, said crimp control rollbeing spaced from said feed rolls along said channel, the portion ofsaid channel between the feed rolls and the crimp control roll defininga confined crimping zone, whereby continuous filament yarn is fed intosaid crimping zone by the feed rolls against a core of crimped yarntherein causing the yarn to collapse longitudinally and fold overforming crimps which become part of said core and the crimps arepartially set in the crimping zone, the portion of said channel betweenthe crimp control roll and the end of the chamber opposite the feedrollS defining a setting zone, whereby said core is fed into saidsetting zone by the crimp control roll and the crimps are fully settherein; means for rotatably driving said pair of feed rolls at the samerotational velocity; and means for rotatably driving said crimp controlroll independently of said feed rolls, whereby the pressure on thecrimped yarn core in said crimping zone may be controlled by regulatingthe relative rotational velocities of the feed rolls and the crimpcontrol roll.
 18. A stuffer crimper as recited in claim 17, wherein saidshort cross-sectional dimension is in the range of from about 0.100 inchto about 0.170 inch.
 19. A stuffer crimper as recited in claim 17,wherein said ratio is in the range of from about 0.001 to about 0.004.20. A stuffer crimper as recited in claim 19, wherein said shortcross-sectional dimension is about 0.160 inch.
 21. A stuffer crimper asrecited in claim 1, further comprising a cooling tower affixed at oneend thereof to said chamber at the end of the chamber opposite said feedrolls and having a channel extending therethrough aligned with saidchamber channel, said tower channel defining a cooling zone, whereby thecrimped yarn core is fed into said cooling zone after passage throughsaid setting zone and the yarn is cooled therein.
 22. A stuffer crimperas recited in claim 21, further comprising means for withdrawing yarnfrom said tower channel.
 23. A stuffer crimper as recited in claim 22,wherein said withdrawing means comprises a winder.